Elevator systems are provided with safety systems for safe operation. These safety systems typically are made up of safety elements connected in series. These safety elements can, for example, monitor the condition of shaft or car doors. Electromechanical safety circuits or even bus-based safety circuits are known. The safe operation of such bus-based safety circuits is inspected regularly. The design and testing of such bus-based safety circuits are known from EP 1159218 A1, WO 2010/097404 A1 or WO 2013/020806 A1, for example. From this prior art, however, it is not obvious whether, or to what extent, safety is ensured when connecting or disconnecting temporary participants, such as a manual control device for controlling the elevator system during maintenance or an input device, via which configuration settings can be set for the safety system.